"The most curious circumstance attending this disease, is, that the matter taken from the pock of a Cow, and inserted into the skin of a human being, will produce a disease in that human being, which w…"

"You see by the papers how I'm annoyed by a set of blockheads who write about the imperfection of the cowpox, as a vaccine, without any knowledge scarcely of its phenomena."

"The human mind is capable of great things; but it is also capable of great errors."

"The most valuable possessions are those which we acquire by our own exertions."

"I have often been surprised at the credulity of mankind; but I have also been surprised at their obstinacy."